Chantilly is a census-designated place in western Fairfax County, Virginia, United States. Chantilly is named after an early 19th century mansion and farm, which in turn took the name of an 18th century plantation that was located in Westmoreland County, Virginia. The name "Chantilly" originated in France with the Château de Chantilly, about 28 miles north of Paris.
The American Registry for Internet Numbers is headquartered adjacent to Washington Dulles International Airport, near Chantilly. Other notable local organisations include; Ellanor C. Lawrence Park – Along Route 28 between Chantilly and Centreville, the park houses athletic fields—including soccer, baseball, and softball fields, trails, and fitness stations; Flat Lick Stream Valley Park; The Steven F. Udvar-Hazy Center annex of the National Air and Space Museum; The Westfields Marriott.
Chantilly is home to the headquarters of the National Reconnaissance Office (NRO), which is one of the "big five" U.S. Intelligence agencies. It designs, builds, and operates the spy satellites of the United States government, and provides satellite intelligence to several government agencies, particularly signals intelligence (SIGINT) to the NSA, imagery intelligence (IMINT) to the NGA, and measurement and signature intelligence (MASINT) to the DIA.
Chantilly has a population of over 23,039 people.